Epidural Metastases and Cord Compression¶

Definition¶

Epidural metastatic disease occurs when tumor extends from the vertebral body or posterior elements into the epidural space, potentially compressing the thecal sac and spinal cord. Malignant epidural spinal cord compression (MESCC) is an oncologic emergency requiring urgent diagnosis and treatment to prevent irreversible neurological injury.

Epidemiology¶

MESCC occurs in approximately 5–10% of cancer patients. The thoracic spine is most commonly affected (60–70%) due to its relative length and the high frequency of thoracic vertebral metastases. Lung, breast, and prostate cancers are the most common primaries.

Bilsky Grading Scale¶

The Bilsky epidural spinal cord compression scale grades the degree of epidural disease on axial MRI:

• Grade 0 — Bone-only disease, no epidural involvement
• Grade 1a — Epidural fat impingement without thecal sac deformation
• Grade 1b — Thecal sac deformation without cord contact
• Grade 1c — Thecal sac deformation with cord contact but without compression
• Grade 2 — Cord compression with visible CSF around the cord
• Grade 3 — Cord compression with no visible CSF around the cord

Imaging Findings¶

MRI¶

MRI with contrast is the definitive study:

• Epidural soft tissue mass — Typically contiguous with vertebral body metastasis, extending posteriorly into the epidural space
• Cord compression — Indentation, displacement, or complete effacement of the CSF space around the cord
• Cord signal change — T2 hyperintensity within the compressed cord indicates edema and suggests impending or existing myelopathy
• Circumferential epidural disease — Tumor may surround the thecal sac, especially from posterior element involvement
• Post-contrast images — Enhancing epidural mass; essential for defining tumor extent

CT¶

• Vertebral body destruction extending into the spinal canal
• Epidural soft tissue mass visible on soft tissue windows
• Useful for surgical planning (bone destruction, pedicle integrity)

Emergency Management¶

MESCC is a time-sensitive emergency:

1. Dexamethasone — High-dose corticosteroids (typically 10 mg IV bolus, then 4 mg every 6 hours) to reduce vasogenic edema
2. Urgent MRI — Whole-spine MRI with contrast within 24 hours (ideally within hours)
3. Radiation therapy — Conventional external beam or stereotactic radiosurgery for radiosensitive tumors
4. Surgery — Decompressive surgery followed by radiation for patients with a single level of compression, good functional status, and >3-month life expectancy, particularly for radiation-resistant tumors

Key Points¶

• MESCC is an oncologic emergency requiring urgent whole-spine MRI
• The Bilsky scale grades epidural compression on axial MRI
• Thoracic spine is most commonly affected
• High-dose corticosteroids should be initiated immediately
• Multifocal epidural disease is present in ~30% of cases
• Surgery followed by radiation provides better outcomes than radiation alone for selected patients

References¶

1. Bilsky MH, Laufer I, Fourney DR, Groff M, Schmidt MH, Varga PP, et al. Reliability analysis of the epidural spinal cord compression scale. J Neurosurg Spine. 2010;13(3):324-8. doi:10.3171/2010.3.SPINE09459. PMID: 20809724.
2. Bai J, Grant K, Hussien A, Kawakyu-O'Connor D. Imaging of metastatic epidural spinal cord compression. Front Radiol. 2022;2:962797. doi:10.3389/fradi.2022.962797. PMID: 37492671.
3. Lo SS, Ryu S, Chang EL, Galanopoulos N, Jones J, Kim EY, et al. ACR Appropriateness Criteria® Metastatic Epidural Spinal Cord Compression and Recurrent Spinal Metastasis. J Palliat Med. 2015;18(7):573-84. doi:10.1089/jpm.2015.28999.sml. PMID: 25974663.
4. Agarwal V, Shah LM, Parsons MS, Boulter DJ, Cassidy RC, Hutchins TA, et al. ACR Appropriateness Criteria® Myelopathy: 2021 Update. J Am Coll Radiol. 2021;18(5S):S73-S82. doi:10.1016/j.jacr.2021.01.020. PMID: 33958120.
5. Hamilton P, Lawrence P, Eisenring CV. Metastatic epidural spinal cord compression. J Surg Case Rep. 2020;2020(8):rjaa217. doi:10.1093/jscr/rjaa217. PMID: 32855794.
6. Epidural spinal cord compression scale. Radiopaedia. Available from: https://radiopaedia.org/articles/epidural-spinal-cord-compression-scale

Related Articles¶

• Vertebral Body Metastases
• Drop Metastases
• Spine Tumors Overview